
After long time evolution, the major axes shrinks to a suitable quantity that the frequency of gravitational wave lies in the frequency band of detector. Following [1]}, [2]}, we assume that \(e\)  keep the constant during inspiral phase, the later major axes can be expressed as
\(a^4 = a_{\mathrm {ini}}^4 - \frac{256}{5}\frac{G^3 \mu M^2}{c^5 (1-e^2)^{7/2}} t~,\) 
